1973

Secretariat won the Belmont Stakes by 31 lengths, winning horse racing’s Triple Crown and setting a still-standing track record of 2 minutes, 24 seconds.

1978

Leaders of the Church of Jesus Christ of Latter-day Saints struck down a policy of excluding Black men from the Mormon priesthood.

1986

The Rogers Commission released its report on the fatal Challenger explosion, criticizing NASA and rocket-builder Morton Thiokol for management problems.